Can Dental Work, Such as Fillings, Lead to Thyroid Issues?

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Our dental health is important and not just because it’s nice to see pearly whites, but also because it has a huge impact on our overall health and wellbeing.

What happens in our mouth has a major influence on other body functions. Even dental work, such as fillings can affect our health in many ways.

Most of us have had some dental work done, but we’ve never asked ourselves whether it could contribute to thyroid problems.

It’s time to address that subject.

The primary objective of this article is to provide answers and explain whether there is a potential for dental work to increase the risk of thyroid problems or aggravate their symptoms.

Can dental fillings affect thyroid health?

Most people have had some form of dental work done with fillings being the most common treatment. Various studies showed that dental fillings could contribute to some health problems, but what about thyroid? Studies on this topic are limited, and current evidence is mixed.

For example, Kisakol carried out a study to observe whether mercury of amalgam fillings is associated with Hashimoto’s disease, an autoimmune condition, and the most common cause of hypothyroidism. The study included 363 patients with Hashimoto’s thyroiditis and 365 healthy controls. Results showed that the frequency of dental amalgam implantation in patients with Hashimoto’s thyroiditis wasn’t statistically and significantly different from healthy controls. Conclusion of the study was that there is no relation of amalgam with Hashimoto’s thyroiditis[i].

However, despite the above-mentioned study showing no relation between dental fillings and a common thyroid-related problem, it doesn’t mean the link is nonexistent. Sterzl et al. conducted a study that inspected the impact of amalgam removal on the levels of anti-thyroid peroxidase (anti-TPO) and anti-thyroglobulin (anti-Tg) antibodies in patients with autoimmune thyroiditis with and without mercury allergy.

Findings revealed that the removal of mercury-containing dental amalgam in patients with mercury hypersensitivity could contribute to the successful treatment of autoimmune thyroiditis. Interestingly, levels of antibodies in patients with or without mercury hypersensitivity who didn’t remove amalgam didn’t change[ii]. Although a small sample, this study did show that there could be a relationship between dental fillings and thyroid problems.

It also revealed that for some patients, management of Hashimoto’s thyroiditis could be improved with the removal of fillings. Of course, more research on this topic is necessary in order to get more solid conclusions.

Why could dental fillings affect thyroid function?

As seen above, there could be a link between dental fillings and thyroid disease. Of course, additional studies are necessary to elucidate this subject and uncover all underlying mechanisms connecting the two. But, it’s impossible not to wonder why dental fillings could affect thyroid function in the first place. What’s the reason behind that unexpected relationship? Although more research is needed, it could be down to mercury. Amalgam fillings contain mercury which is linked to some other health risks, and it comes as no wonder why it could also affect the butterfly-shaped gland.

Various studies confirmed that exposure to mercury could alter thyroid hormone levels. Sun et al. exposed zebrafish embryos to environmentally relevant concentrations of mercury and found that it can alter thyroid hormone levels[iii]. Additionally, Afrifa et al. studied 137 male gold miners at their worksite in Bibiani, Ghana and found that exposure to mercury altered their thyroid hormone concentration[iv].

Therefore, through mercury content dental fillings could have a negative impact on thyroid hormone balance and therefore contribute to thyroid problems. However, as mentioned above, this subject requires further research.

Amalgam is a controversial subject

Dental amalgam fillings are a controversial subject and a matter of many debates among scientists. While some agree, they are harmful to our health others to disagree. For example, in their report, the FDA concluded there is insufficient evidence to support an association between exposure to mercury from dental amalgams and adverse health effects in humans, including sensitive subpopulations[v].

That being said, WHO is not so quick to claim amalgam is entirely harmless. The organization stated that contemporary dental restorative materials, including dental amalgam, are considered to be safe and effective. However, adverse biological reactions to the materials do occur occasionally, and they need to be treated on an individual basis. WHO report also stated the organization recognizes the importance of concern about amalgam and will continue to monitor the safety and effectiveness of this and other dental restorative materials[vi].

On their website, WHO, wrote about mercury in general and explained that it might have toxic effects on the nervous, digestive, and immune system as well as it can affect lungs, eyes, kidneys, and skin. What’s more, WHO considers mercury as one of the top 10 chemicals or groups of chemicals of major public health concern[vii].

A paper from the Journal of Occupational Medicine and Toxicology explains that amalgam may not be as safe as the agencies claim it is. Dental amalgam is the main source of a total mercury burden in the human body. The half-life of mercury in the human brain can last from several years to a few decades, meaning it can accumulate over time due to amalgam exposure. Many studies which claim amalgam is entirely safe to have many methodological flaws[viii].

When it comes to the safety of dental amalgam fillings, the jury is still out there. But, it’s worth mentioning that many dentists don’t recommend these fillings to their patients anymore.

Should I have my amalgam fillings removed?

Now that you know dental amalgam fillings could have a negative impact on thyroid you’re probably wondering whether you should have them removed. This is a complicated subject, and, at this point, there is no right or wrong answer. You see, sometimes having your amalgam fillings removed can do more harm than good. In some instances, removal of amalgam fillings can amplify the autoimmune response of a person who has Hashimoto’s thyroiditis or Graves’ disease, an autoimmune condition and the most common cause of hyperthyroidism.

If you want to get your amalgam fillings removed, you should discuss this subject with your doctor or your dentist. Speaking of dentists, you should see the one who takes the proper precautions when removing them. For instance, a biological dentist is a good idea.

What about root canals?

A root canal is a dental treatment whose main purpose is to eliminate bacteria from the infected root canal, prevent reinfection of the tooth, and save the natural tooth. During the treatment, the infected or inflamed pulp is removed, and the inside of the tooth is carefully cleaned, disinfected, filled, and finally sealed.

In most cases, root canals are necessary for a cracked tooth from injury or genetics, issues from a previous filing, and due to a deep cavity[ix]. Numbers show that 15.1 million root canal treatments are performed annually in the United States. Of these, 72% were performed by general dentists, while 28% were performed by endodontists[x].

Root canals are generally considered safe, and adverse effects may occur. Unfortunately, the impact of root canals on thyroid function and hormones produced by the butterfly-shaped gland is poorly studied. Hopefully, things will change. The main controversy associated with root canals is whether all of the bacteria can be eradicated successfully. More precisely, is it possible to sterilize root canals permanently? Let’s not forget that Dr. Weston Price investigated this subject. A Canadian dentist who is best known for his theories on the relationship between nutrition, dental health, and physical health suggested that bacteria trapped in dentinal tubules during root canal treatment could “leak” and cause almost any type of degenerative systemic disease[xi]. Basically, root canal treatment may not sterilize the area permanently. Bacteria can still affect the nervous system and other systems in the body resulting in the onset of autoimmune reactions[xii].

However, this does not necessarily mean the root canal is the trigger of thyroid problems. We need more studies on this subject to get a detailed insight into the potential relationship between a root canal and thyroid diseases. But, if you have one or more root canals and also happen to have some thyroid-related problem which doesn’t improve with regular treatment, you may want to consider discussing this topic with your dentist.

Thyroid problems and dental health

Since we’re discussing the impact of dental treatments on thyroid problems, it’s impossible not to address the potential connection between diseases affecting butterfly-shaped gland and dental health. It seems like dental health, and our thyroid has a stronger relationship than most people think. For example, Zahid et al. found that thyroid diseases may affect the status of periodontal diseases, particularly the hypothyroid state. The uncontrolled thyroid may result in the destruction of the periodontium, supporting structure of a tooth[xiii]. Patients with hypothyroidism should see their doctor regularly and focus on dental health as well. That way, they can significantly reduce the risk of periodontal disease.

Regular checkups at the dentist’s office are also important because hypothyroid men and women are more prone to inflammation and infections. That being said, patients with hyperthyroidism are also prone to infections and slow wound healing after dental procedures[xiii].

The relationship between thyroid problems and dental health appears to be a two-way street. For example, impacted teeth can induce inflammation around the root of other teeth and lead to periodontal disease and other problems. Bacteria from the oral cavity can affect gut health and trigger an autoimmune response. This means common dental problems could contribute to the development or progression of Hashimoto’s thyroiditis and Graves’ disease.

It is also worth mentioning that fillings, onlays, braces, bridges, plastic aligners such as Invisalign, and other materials used in dental treatments may trigger an autoimmune response in some patients. When the autoimmune response occurs, it’s a sign of the incompatibility of the specific material to a patient’s biochemical makeup[xiii].

Dental health tips

Strong teeth and gums are important for our overall health and wellbeing. They also boost our confidence. Taking care of your dental health could also decrease the risk of various health problems. At the same time, it could also mean a lot to a healthy thyroid. Below, you can see some useful tips that will help you take care of your dental health properly:

  • Brush your teeth two to three times a day and make sure you avoid going to bed without brushing your teeth to get rid of germs and plaque that accumulated during the day
  • Move your brush in gentle, circular motions
  • When brushing your teeth, you should not neglect your tongue
  • Flossing should be an inseparable part of your oral care routine
  • Drink more water
  • Eat crunchy fruits and vegetables
  • Limit intake of sugary and acidic foods
  • See your dentist at least twice a day
  • Try not to use the popular teeth whitening kits which may have a counterproductive effect
  • Limit or avoid the intake of alcohol and soda


Various factors affect thyroid function, but most of us have never wondered if dental treatments such as fillings could do the same.

Evidence on this subject is mixed, but insufficient to claim yes or no.

The truth is that more studies are needed to learn whether dental treatments could contribute to thyroid diseases.


[i] Kisakol G. (2014). Dental amalgam implantation and thyroid autoimmunity. Bratislava Lekarske Listy, 115(1):22-4. Retrieved from:

[ii] Sterzl L, Prochazkova J, Hrda P, et al. (2006). Removal of dental amalgam decreases anti-TOP and anti-Tg antibodies in patients with autoimmune thyroiditis. Neuro Endocrinology Letters, 27 Suppl 1:25-30. Retrieved from:

[iii] Sun Y, Li Y, Liu Z, Chen Q. (2018). Environmentally relevant concentrations of mercury exposure alter thyroid hormone levels and gene expression in the hypothalamic-pituitary-thyroid axis of zebrafish larvae. Fish Physiology and Biochemistry, 44(4):1175-1183. Doi: 10.1007/s10695-018-0504-2. Retrieved from:

[iv] Afrifa, J., Ogbordjor, W. D., & Duku-Takyi, R. (2018). Variation in thyroid hormone levels is associated with elevated blood mercury levels among artisanal small-scale miners in Ghana. PloS one13(8), e0203335. doi:10.1371/journal.pone.0203335. Retrieved from:

[v] White paper: FDA update/review of potential adverse health risks associated with exposure to mercury in dental amalgam (2009). FDA. Retrieved from:

[vi] WHO consensus statement on dental amalgam (1997), FDI. Retrieved from:

[vii] Mercury and health (2017), WHO. Retrieved from:

[viii] Mutter J. (2011). Is dental amalgam safe for humans? The opinion of the scientific committee of the European Commission. Journal of occupational medicine and toxicology (London, England)6(1), 2. doi:10.1186/1745-6673-6-2. Retrieved from:

[ix] What is root canal? American Association of Endodontists. Retrieved from:

[x] Endodontic treatment statistics. American Association of Endodontists. Retrieved from:

[xi] Root canal safety. American Association of Endodontists. Retrieved from:

[xii] Zahid TM, Wang BY, Cohen RE. (2011). The effects of thyroid hormone abnormalities on periodontal disease status. Journal of the International Academy of Periodontology, 13(3):80-5. Retrieved from:

[xiii] Chandna, S., & Bathla, M. (2011). Oral manifestations of thyroid disorders and its management. Indian journal of endocrinology and metabolism15(Suppl 2), S113–S116. doi:10.4103/2230-8210.83343. Retrieved from:

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